I am running CiviCRM 4.7.15 and Joomla 3.6.5 and I am unable to select a profile when I turn on online registration for an event. I can select a profile for a contribution page but just not events.

I went back to Test site that was running CiviCRM 4.5.4, and I could select profiles.  I upgraded to CiviCRM 4.6.9, and I was no longer able to select the profiles.  Version 4.6.9 post upgrade notes indicated that there were changes for the event workflow templates.  Not sure if that is related.

I tried this on the CiviCRM Joomla demo site, currently running v4.6.18, and I could select profiles.  However, the major difference is that I have several of the CiviCRM extensions installed on my Test and Prod sites.

I see similar posts, but some answers discuss Wordpress and others indicate a fix back in v4.5.4.

Can anyone point me in the right direction? 

Thank you in advance for any assistance.